Countercurrent chromatography (CCC) is a support-free liquid–liquid chromatography using two immiscible liquid phases. ATPS has been used as a CCC platform mainly for the separation and purification of biological materials. CCC with ATPS also has great potential as a chromatographic method that allows simultaneous separation and enrichment of metal ions through pH-peak-focusing technique. This chapter begins by describing the optimum operating conditions for a type-J coil planet CCC with ATPSs consisting of PEG and Na2SO4. It then proceeds to explain the multistep pH-peak-focusing CCC developed for the separation and enrichment of metal ions with a PEG/Na2SO4 ATPS. The resolution of a type-J coil planet CCC increases with an increase in the rotation speed of the polytetrafluoroethylene tube column holder due to a drastic increase in the theoretical plate number. This is caused by the increase in the number of the partition processes and the decrease in the size of the phase droplets due to more intense agitation, which increases the mass transfer rate of solute compounds between the mobile phase (salt-rich phase) and the stationary phase (PEG-rich phase). On the other hand, the increase in the flow rate of the mobile phase does not appreciably affect the resolution of CCC. In multistep pH-peak-focusing CCC, metal ions in a sample solution are trapped at the top of the CCC column filled with a basic stationary phase containing an extraction reagent by complexation with it. Then, the mobile phases of which the pH values have been adjusted with suitable buffer reagents are pumped into the column stepwise in order of decreasing pH. Each metal ion is concentrated at a pH border formed between the zones of different pH in the CCC column through extraction as the metal complexes with an extracting agent into the stationary phase at the front side (higher pH) of the border and back extraction by the dissociation of the complexes into the mobile phase at the rear side (lower pH) of the border, eluting from the column together with the pH border. Enrichment as well as mutual separation of metal ions can be achieved by multistep pH-peak-focusing CCC. The mechanism of formation of the pH borders and the potential of multistep pH-peak-focusing CCC for preparative-scale metal separation are also discussed.